Feed device for rock-drills



2 SHEETS-SHEET l.

6: Wm vfilarw/ S FISHER FEED.DEVICE FOR ROCK omus.

APPLICATION FILED APR. 4, 1919.

Patented Apr. 19, 1921.

s; FISHER. FEED DEVICE FOR ROCK- DR |L LS. APPLICATION H LED APR. 4, W4 9.

Patented Apr. 19, 1921.

2 SHEETS-SHEET 2 UNITED STATES SEG-UIN FISHER, OF JOHANNESBURG, TRANSVAAL, SOUTH AFRICA.

FE D DEVICE FOR ROCK-DRILLS.

, Specification of Letters Patent.

Patented Ap r.19, 1921.

Application filed April 4, 1919'. Serial No. 287,399.

T all whom it may concern:

Be it known that I, SEGUIN FISHER, a Brlt- "ish subject, residing at Ferreira Deep Limited, Johannesburg, Transvaal, Province of the Union of South Africa, have invented certain new and useful Improvements in Feed Devices for Rock-Drills, of which the following is a specification;

The present invention relates to feed devices for rock drills. A purpose of'the 1nvention is to provide a simple and inexpensive feeding device applicable to light hammer drills designed to be held in the "hand whereby such drills may be fed without subjecting the operator to injurious vibration. Another object is to enable the average feeding pressure to be readily adjusted as is necessary for various positions of the drill.

In the accompanying drawings, Figure I shows the invention embodied in a support including a cradle adapted to be carried on a frame or column.

Fig. II is a longitudinal section of the cradle and allied parts.

Fig. III shows the same with the parts differently positioned.

Fig. IV shows a feeding tool.

Fig. V shows a modified form in connection with a bar adapted to be secured in a hole in the rock as described in a co-pending application filed by me.

Fig, VI is a cross section of the device taken through the cradle and drill.

Referring toFig. I, 1 indicates a cradle consisting of a tube .provided with trunnions 2 for mounting it in a supporting frame 3. Within the tube slides a slipper 4. formed with a lateral arm 5 which extends through a longitudinal slot 6 in the tube 1 and carries clamps 7 in which the hammer drill 8 is clipped.

The slipper 4 is fed forward by means of a spring capable of considerable deformation and operated by an anchor or abutment which is movable forwardly to stress the spring and so apply feeding force to the slipper.

In the constructions shown the anchor is arranged to be pressed forward periodically by hand and to be locked to the cradle after each such movement. In Figs. II and III, 9 indicates the anchor consisting of a rod extending through the slipper 4. and extended laterally toward each end to form pawls 10, 11, capable of engaging with a rack 12 formed by cutting notches in one side of the cradle slot 6. A coil spring 13 is secured at one end to a collar 14 on the rod 9 and at the other end 15 to the slipper and is initially twisted, thus giving the pawls the required tendency to enter and engage with the rack 12. The rotational movement of the pawls is limited by means of a slit 16 in the slipper 4, through which the rear pawl 11 projects and which is elongated to permit relative longitudinal movement of the rod 9'andthe slipper 1. To permit the anchor rod 9 to be fed forward the pawls 10, 11, are first rotated out of the rack 12 and the rod 9 is pressed forward by hand. The same spring 13 acts as the feed spring, beingcompressed when the rod 9 is thus pushed forward and engaged with the rack as indicated in Fig. III. The spring is thereby caused to press on the slipper 1 to urge the drill forward.

The provision of a pawl at each end of the anchor rod 9 permits the length of feeding movement to exceed the length of the rack 12, the pawls being so spaced that before the forward pawl 10 leaves the rack 12, the rear pawl 11 engages with the same. When the rear pawl is within the cradle tube 1, the anchor rod 9 is actuated by a tool which can also pass into the cradle tube. Said tool is shown in Fig. IV and is formed with-a handle 17 and a shank 18.- The latter is hollowed at the end 19 and slotted out at 20 to engage the pawl 11. It can thus both press forward and rotate the rod 9 and forms virtually a removable extension of said rod 9. The side of the cradleslot 6 is sloped away at 21 to facilitate the pawls 10, 11 entering said slot.

The spring 13 is made of considerable length so as to maintain a fairly uniform pressure between each feeding movement of the anchor 9. By compressing the spring to a greater or less extent at ,each movement the average feeding pressure may be satisfactorily adjusted for the work in hand. In

substantial distance; means in connection with the spring enabling the spring to be deformed manuallyand independently of the drill to cause it to feed the drill and means for repeatedly anchoring said lastmentioned means to the cradle in its various progressing positions.

2. A feed device for a hammer drill, com.-. prising a cradle; a drill carrying slipper slidably mounted thereon; an anchor device; a feed spring between the cradle and the slipper such as to permit substantial relative feeding movementsof said parts, said anchor device being adapted to be thrust forward manually and independently of movement of the drill carried by the slipper to atension the spring for feeding pressure; and meansv to secure the anchor tothe cradle the rackand a .feed spring between the said means. being manually releasable.

3. A feed device for:- a hammer drill con sisting of a cradle on which the drill is slidable for feeding movement and provided with a'rack, a spring anchormovable over I the same, a feedspring between the anchor and the drill, said anchor havin I spaced one behind the other in theirection pawls 4:. A feed device for a hammer drill consisting of a cradle provided -with a rack, a slipper slidable on the cradle'for feeding movement and prevented from rotating thereon, an anchor slidable with respect to the slipper and provided with a pawl. for engaging the rack. and a spring secured to the anchor and the slipper and serving to feed the latter forward, said spring being torsioned to cause the pawl, to engage the rack. V

5. In a feed device for a hammer drill, the. combination of acradle having a. slot and formed with a rack, a tubular slipper sliding thereon and having a lug extending through said slot; an anchor rod in, the slipper and provided with a pawl to engage anchor rod and the slipper. V

6. A feed tool. for a feed device as claimed; in claim 5, having a shankadapted to enter the slipper and engaging the anchor bar. for pressing-forward and rotating the same. In testimony whereof I afiix my signature. SEQUIN, FISHER. 

